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Underwater acoustic metamaterials

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National Science Review 2023年第6期10卷 258-280页

作者： Erqian Dong Peizheng Cao Jinhu Zhang Sai Zhang Nicholas x.fang Yu Zhang Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education College of Ocean and Earth Sciences Xiamen University State Key Laboratory of Marine Environmental Science Xiamen University School of Physics and Electronic Engineering Jiangsu University Department of Mechanical Engineering Massachusetts Institute of Technology

Acoustic metamaterials have been widely investigated over the past few decades and have realized acoustic parameters that are not achievable using conventional *** demonstrating that locally resonant acoustic metamaterials are capable of acting as subwavelength unit cells,researchers have evaluated the possibility of breaking the classical limitations of the material mass density and bulk *** with theoretical analysis,additive manufacturing and engineering applications,acoustic metamaterials have demonstrated extraordinary capabilities,including negative refraction,cloaking,beam formation and super-resolution *** to the complexity of impedance boundaries and mode transitions,there are still challenges in freely manipulating acoustic propagation in an underwater *** review summarizes the developments in underwater acoustic metamaterials over the past 20 years,which include underwater acoustic invisibility cloaking,underwater beam formation,underwater metasurfaces and phase engineering,underwater topological acoustics and underwater acoustic metamaterial *** the evolution of underwater metamaterials and the timeline of scientific advances,underwater acoustic metamaterials have demonstrated exciting applications in underwater resource development,target recognition,imaging,noise reduction,navigation and communication.

关键词： underwater acoustic metamaterials invisibility cloaking beam formation topological acoustics metasurfaces absorbers

Physical modeling and validation of porpoises' directional emission via hybrid metamaterials

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National Science Review 2019年第5期6卷 921-928页

作者： Erqian Dong Yu Zhang Zhongchang Song Tianye Zhang Chen Cai Nicholas x.fang Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education College of Ocean and Earth SciencesXiamen University Department of Mechanical Engineering Massachusetts Institute of Technology State Key Laboratory of Marine Environmental Science Xiamen University Biology Department Woods Hole Oceanographic Institution

In wave physics and engineering, directional emission sets a fundamental limitation on conventional simple sources as their sizes should be sufficiently larger than their *** metamaterial and animal biosonar both show potential in overcoming this *** metamaterials arranged in periodic microstructures face great challenges in realizing complex and multiphase biosonar ***, we proposed a physical directional emission model to bridge the gap between porpoises’ biosonar and artificial *** by the anatomical and physical properties of the porpoise’s biosonar transmission system, we fabricated a hybrid metamaterial system composed of multiple composite *** validated that the hybrid metamaterial significantly increased directivity and main lobe energy over a broad bandwidth both numerically and *** device displayed efficiency in detecting underwater target and suppressing false target *** metamaterial-based physical model may be helpful to achieve the physical mechanisms of porpoise biosonar detection and has diverse applications in underwater acoustic sensing, ultrasound scanning, and medical ultrasonography.

关键词： porpoise’s physical model metamaterials biosonar directional emission

Muscle-fiber array inspired, multiple-mode, pneumatic artificial muscles through planar design and one-step rolling fabrication

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National Science Review 2021年第10期8卷 68-78页

作者： Jiang Zou Miao Feng Ningyuan Ding Peinan Yan Haipeng xu Dezhi Yang Nicholas x.fang Guoying Gu xiangyang Zhu State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Department of Mechanical Engineering Massachusetts Institute of Technology Robotics Institute School of Mechanical Engineering Shanghai Jiao Tong University

Advances in development of artificial muscles have enabled creation of soft robots with biological dexterity and self-adaption in unstructured environments; however, production of scalable artificial muscles with multiple-mode actuations remains elusive. Inspired by muscle-fiber arrays in muscular hydrostats, we present a class of versatile artificial muscles called MAIPAMs(muscle-fiber array inspired pneumatic artificial muscles), capable of multiple-mode actuations(such as parallel elongation-bending-spiraling actuations, 10 parallel bending actuations and cascaded elongation-bending-spiraling actuations). Our MAIPAMs consist of active 3 D elastomer-balloon arrays reinforced by a passive elastomer membrane,achieved through a planar design and one-step rolling fabrication approach. We introduce prototypical designs for the MAIPAMs and demonstrate their muscle-mimic structures and versatility, as well as their scalable ability to integrate flexible but non-stretchable layers for contraction and twisting actuation modes and compliant electrodes for self-sensing. We further demonstrate that this class of artificial muscles shows potential for versatile robotic applications, such as carrying a camera for recording videos, gripping or manipulating objects, and climbing a pipe-line.

关键词： soft robotics pneumatic artificial muscles multiple-mode actuations bio-inspired design

Modified astrophysical S-factor of 12C+12C fusion reaction at sub-barrier energies

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Chinese Physics C 2020年第11期44卷 189-207页

作者： Y.J.Li x.fang B.Bucher K.A.Li L.H.Ru x.D.Tang China Institute of Atomic Energy Beijing 102413China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China Idaho National Laboratory Idaho FallsID 83415USA Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

The 12C+12C fusion reaction plays a crucial role in stellar evolution and *** main open reaction channels includeα,p,n,and *** more than a half century of efforts,large differences remain among the experimental data of this reaction measured using various *** this work,we analyze the existing data using a statistical *** calculation shows the following:1)the relative systematic uncertainties of the predicted branching ratios decrease as the predicted ratios increase;2)the total modified astrophysical S-factors(S^* factors)of the p andαchannels can be obtained by summing the S^* factors of their corresponding ground-state transitions and the characteristicγrays,while taking into account the contributions of the missing channels to the *** applying corrections based on branching ratios predicted by the statistical model,an agreement is achieved among the different data sets at Ecm>4 MeV,while some discrepancies remain at lower energies,suggesting the need for better measurements in the near *** find that the S^* factor recently obtained from an indirect measurement is inconsistent with the direct measurement value at energies below 2.6 *** recommend upper and lower limits for the 12C+12C S^* factor based on the existing models.A new 12C+12C reaction rate is also recommended.

关键词： carbon burning 12C+12C fusion statistical model quasi-molecular resonance astrophysical S-factor reaction rate stellar evolution

Additive manufacturing of high aspect-ratio structures with self-focusing photopolymerization

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Light(Advanced Manufacturing) 2022年第3期3卷 120-149页

作者： Mingyu Yang Kavin Kowsari Nia O.Myrie Daniela Espinosa-Hoyos Anna Jagielska Seok Kim Nicholas x.fang Krystyn J.Van Vliet Harvard-MIT Health Sciences and Technology Massachusetts Institute of TechnologyCambridgeMA02139United States Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMA02139United States Department of Radiology Brigham and Women’s HospitalHarvard Medical SchoolBostonMA02115United States Department of Biological Engineering Massachusetts Institute of TechnologyCambridgeMA02139United States Walter H.Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University School of MedicineAtlantaGA30332United States Department of Chemical Engineering Massachusetts Institute of TechnologyCambridgeMA02139United States Department of Materials Science&Engineering Massachusetts Institute of TechnologyCambridgeMA02139United States Department of Mechanical Engineering Changwon National UniversityChangwon51140South Korea

Photocrosslinkable polymers have been exploited to attain impressive advantages in printing freestanding,micrometer-scale,mechanically compliant ***,a more integrated understanding of both the polymer photochemistry and the microfabrication processes could enable new strategic design avenues,unlocking far-reaching applications of the light-based modality of additive *** promising approach for achieving high-aspect-ratio structures is to leverage the phenomenon of light self-trapping during the photopolymerization *** this review,we discuss the design of materials that facilitate this optical behavior,the computational modeling and practical processing considerations to achieve high aspect-ratio structures,and the range of applications that can benefit from architectures fabricated using light self-trapping-especially those demanding free-standing structures and materials of stiffnesses relevant in biological *** interactions exist among material attributes,including polymer composition,and processing parameters such as light *** identify strong opportunities for predictive design of both the material and the ***,this perspective describes the wide range of existing polymers and additive manufacturing approaches,and highlights various future directions to enable constructs with new complexities and functionalities through the development of next-generation photocrosslinkable materials and micromanufacturing methods.

关键词： Additive manufacturing Optical waveguide High aspect-ratio Biocompatible structures Polymer photochemistry

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1950年代中国农村的接生婆与国家纪律

文化纵横 2017年第5期 14-14页

作者：草苍 x.fang

现代国家的形成和发展与纪律观念在社会的生根息息相关,如无纪律,则军队作战、官僚行政、医院救治等都难以形成一个令行禁止的系统,高效的国家机器和具有应对问题能力的社会组织是现代国家不可或缺的一部分。新中国建国之初,也面对着如... 详细信息

现代国家的形成和发展与纪律观念在社会的生根息息相关,如无纪律,则军队作战、官僚行政、医院救治等都难以形成一个令行禁止的系统,高效的国家机器和具有应对问题能力的社会组织是现代国家不可或缺的一部分。新中国建国之初,也面对着如何将纪律引入到党政系统和社会组织之中,并使之扎根于中国社会的问题。

关键词：纪律观念现代国家中国农村 50年代社会组织官僚行政国家机器中国社会

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直肠癌：原发肿瘤T2WI直方图是否有助于预测淋巴结转移的存在

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国际医学放射学杂志 2020年第1期 122-122页

作者： L.Yang D.Liu x.fang Z.Wang Y.xing L.Ma 张立武 Department of Radiology West China Hospital Sichuan University

目的探讨直肠癌原发肿瘤TWI直方图特征与局部淋巴结转移的相关性。方法回顾性纳入88例经病理证实的直肠腺癌病人,所有病人均接受手术切除和术前直肠MRI

关键词：直方图 T2WI 纹理分析直肠癌原发肿瘤淋巴结转移

基于CT检查采用人工智能预测胰腺导管腺癌淋巴结转移

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国际医学放射学杂志 2023年第2期 229-229页

作者： Y.Bian Z.L.Zheng x.fang H.Jiang M.M.Zhu J.Y.Yu 李知琪

摘要虽然深度学习给医疗保健带来了革命性的变化，但依赖于手动选择横断面影像和分割仍是其方法学壁垒。目的研发和验证一种基于CT影像的肿瘤和淋巴结（LN）影像

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Preparation and applications of calcium ferrite as a functional material:A review

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 292-310页

作者： xiuli Han Bowen Duan Lei Liu Shilong fang Weiwei Wang College of Mining Engineering North China University of Science and TechnologyTangshan 063210China Collaborative Innovation Center of Green Development and Ecological Restoration of Mineral Resources of Hebei Province Tangshan 063210China Key Laboratory of Mining Development and Security Technology of Hebei Province Tangshan 063210China

Calcium ferrite(CF)is recognized as a potential green and efficient functional material because of its advantages of magnetism,electrochemistry,catalysis,and biocompatibility in the fields of materials chemistry,environmental engineering,and ***-fore,the obtained research results need to be systematically summarized,and new perspectives on CF and its composite materials need to be *** on the presented studies of CF and its composite materials,the types and structures of the crystal are *** addition,the current application technologies and theoretical mechanisms with various properties in different fields are ***,the various preparation methods of CF and its composite materials are elaborated in *** importantly,the advantages and disadvantages of the synthesis methods of CF and its composite materials are discussed,and the existing problems and emerging challenges in practical production are ***,the key future research directions of CF and its composite materials have been prospected from the potential application technologies to provide references for its synthesis and efficient utilization.

关键词： calcium ferrite mineral functional materials preparation application perspectives

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